public class SampleApexModel {
    Public String field1 {get; set;}
    Public String field2 {get; set;}
    Public Integer field3 {get; set;}
    Public Integer field4 {get; set;}
    
    public SampleApexModel(){
        field1 = field2 = 'No Value';
        field3 = field4 = 0;
    }
    public SampleApexModel(String f1, String f2, Integer f3, Integer f4){
        field1 = f1;
        field2 = f2;
        field3 = f3;
        field4 = f4;
    }  
}